Black pepper (Piper nigrum) fruit-based gold nanoparticles (BP-AuNPs): Synthesis, characterization, biological activities, and catalytic applications – A green approach

Abstract

Abstract As compared to conventional techniques, currently nanotechnology has gained significant attention of scientists for the development of plant-based natural nanoparticles (NPs) due to their safety, effectiveness, and environment friendly nature. The current study was aimed for development, characterization (energy-dispersive X-ray, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, and scanning electron microscopy), and evaluation of the biological efficiency of black pepper (BP; Piper nigrum) fruit-based gold NPs (BP-AuNPs) through different in vitro and in vivo assays. BP extract revealed maximum antibacterial and antifungal potential against Escherichia coli (24 mm) and Aspergillus flavus (47 mm), respectively. However, BP-AuNPs (200 µg·mL−1) inhibited the urease, xanthine oxidase, and carbonic acid-II activities with a percent inhibition of 83.11%, 91.28%, and 86.87%, respectively. Further, the anti-inflammatory effect of BP extract at the dose of 100 mg·kg−1 was 72.66%, whereas for BP-AuNPs it was noticed to be 91.93% at the dose of 10 mg·kg−1. Similarly, the extract of BP and prepared AuNPs demonstrated significant (p < 0.01) sedative effect at all tested doses. The BP-AuNPs catalytically reduced methyl orange dye. Results suggest that BP-AuNPs possess significant biological activities, and further studies must be conducted to identify the probable mechanism of action associated with these activities.